thermal compound, between it and the CPU surface. Starting with absolutely clean surfaces, the thermal compound needs to be only a rather thin film. No way is more goop better. If you select a conductive paste then be careful to not get it anywhere but on the actual mating surfaces. It is NOT a squeeze out between the two surfaces process.

Keep in mind that the interior ambient air temperature that the HSF is transfering heat to should be only about 12 to 20 F degrees above your room ambient. Therefore cooling the entire interior will also lower CPU temps.

Yep Athlons run hot. If it is one that does NOT have the heat spreader to increase the effective surface of the CPU, the heat is being dissipated over about a one square inch surface. Thus the thermal transfer from the CPU to the Heatsink is very critical. Intel has used the heat speader for years. I understand that some of the 32 bit Athlons are now using them. The AMD 64 bitters all use heatspreaders.